在学校上《数据结构》的时候老师第一次留的作业：
#include<stdio.h
#include<stdlib.h
#include<string.h
#define OK 1
#define ERROR 0
#define ListNodeLen sizeof(ListNode)
struct listNode { /* self-referential structure */
char name[20];
char teleNo[15];
char Email[35];
struct listNode *nextPtr;
};
typedef struct listNode ListNode;
typedef ListNode *ListNodePtr;
void insert( ListNodePtr *, char *, char *, char * );
int del( ListNodePtr *, char * );
ListNodePtr search( ListNodePtr *, char *);
int isEmpty( ListNodePtr );
void printList( ListNodePtr );
void instructions( void );
ListNodePtr load( void );
void save( ListNodePtr );
void creatfile( void );
int main()
{
ListNodePtr startPtr=NULL, elemPtr;
char judge, choice;
char item1[20], item2[15],item3[35];
if( (startPtr=load())==NULL ) creatfile(); /* 文件不存在则创建 */
instructions(); /* 显示菜单 */
printf( "\nCommand " ); /* 命令提示符 */
scanf( "%c", &choice );
if(choice='A'&&choice<='Z') choice=choice+32; /* 大小写转换 */
while( choice!='q' ) {
switch( choice ) {
case 'a':
printf( "请输入要添加的姓名、电话号码和Email:(eg. Name TelNo. Email)\n" );
scanf( "\n%s",item1 );
scanf( "\n%s",item2 );
scanf( "\n%s",item3 );
insert( &startPtr, item1, item2, item3 );
break;
case 'd':
if( !isEmpty( startPtr )) {
printf("请输入要删除的姓名: ");
scanf("\n%s",item1);
if( del( &startPtr,item1)) {
printf("%s 已经被删除.\n",item1 );
}
else
printf("%s 未找到\n\n",item1 );
}
else
printf("电话本是空的！\n\n");
break;
case 's':
if( !isEmpty( startPtr )) {
printf( "请输入要查找的姓名: ");
scanf( "\n%s",item1 );
if( (elemPtr=search( &startPtr, item1 ))!=NULL ) {
printf( "\n%-20s%-15s%-35s\n", "姓名:", "电话号码:", "Email:" );
printf( "%-20s%-15s%-35s\n", elemPtr-name, elemPtr-teleNo, elemPtr-Email );
}
else
printf( "%s 未找到！\n\n", item1 );
}
else
printf("电话本是空的！\n\n");
break;
case 'p':
printList( startPtr );
break;
default:
printf( "无效的选择！\n\n" );
instructions();
break;
}
printf( "\nCommand " );
scanf( "\n%c",&choice );
if(choice='A'&&choice<='Z') choice=choice+32; /* 大小写转换 */
}
printf( "是否保存(Y/N)? " );
scanf( "\n%c", &judge );
if( judge=='Y'||judge=='y' )
save( startPtr );
printf( "结束！\n" );
return OK;
}
/* Print the instructions */
void instructions( void )
{
printf("q. Quit(退出)"
"\ta. Add(添加)"
"\td. Delete(删除)"
"\ts. Search(查找)"
"\tp. Print(打印)\n"
"请选择命令:(Q/q、A/a、D/d、S/s、P/p)\n");
}
/* Insert a new value into the list in sorted order */
void insert( ListNodePtr *sPtr, char value1[], char value2[], char value3[] )
{
ListNodePtr newPtr, previousPtr, currentPtr;
newPtr=(ListNodePtr)malloc( ListNodeLen );
if( newPtr!=NULL ) { /* is space available */
strcpy(newPtr-name,value1);
strcpy(newPtr-teleNo,value2);
strcpy(newPtr-Email,value3);
newPtr-nextPtr=NULL;
previousPtr=NULL;
currentPtr=*sPtr;
while(currentPtr!=NULL&&strcmp(value1,currentPtr-name)==1) {
previousPtr=currentPtr; /* walk to ... */
currentPtr=currentPtr-nextPtr; /* ... next node */
}
if( previousPtr==NULL ) {
newPtr-nextPtr=*sPtr;
*sPtr=newPtr;
}
else {
previousPtr-nextPtr=newPtr;
newPtr-nextPtr=currentPtr;
}
}
else
printf( "%s 无法添加,没有可用内存！\n", value1 );
}
/* Delete a list element */
int del( ListNodePtr *sPtr, char value[] )
{
ListNodePtr previousPtr, currentPtr, tempPtr;
if( !strcmp(value,(*sPtr)-name) ) {
tempPtr=*sPtr;
*sPtr=(*sPtr)-nextPtr; /* 删除头结点 */
free( tempPtr ); /* 释放头结点 */
return OK;
}
else {
previousPtr=*sPtr;
currentPtr=(*sPtr)-nextPtr;
while( currentPtr!=NULL&&strcmp(currentPtr-name,value) ) {
previousPtr=currentPtr; /* 移动 ... */
currentPtr=currentPtr-nextPtr; /* ... 下一个结点 */
}
if( currentPtr!=NULL ) {
tempPtr=currentPtr;
previousPtr-nextPtr=currentPtr-nextPtr;
free( tempPtr );
return OK;
}
}
return ERROR;
}
/* Search element in the list */
ListNodePtr search( ListNodePtr *sPtr, char value[] )
{
ListNodePtr currentPtr;
if( !strcmp(value,(*sPtr)-name) )
return *sPtr;
else {
currentPtr=(*sPtr)-nextPtr;
while( currentPtr!=NULL&&strcmp(currentPtr-name,value) ) {
currentPtr=currentPtr-nextPtr; /* ... 下一个结点 */
}
if( currentPtr!=NULL ) {
return currentPtr;
}
}
return NULL;
}
/* Return 1 if the list is empty, 0 otherwise */
int isEmpty( ListNodePtr sPtr )
{
return sPtr==NULL;
}
/* Print the list */
void printList( ListNodePtr headPtr )
{
ListNodePtr currentPtr=headPtr;
int i=0;
if( currentPtr==NULL )
printf( "电话本是空的.\n\n" );
else {
printf( "\n%31s\n", "********" );
printf( "%30s\n", "电话本" );
printf( "%31s\n", "********" );
printf( "%-20s%-15s%-35s\n", "姓名:", "电话号码:", "Email:" );
printf( "------------------------------------------------------------\n" );
while( currentPtr!=NULL ) {
printf( "%-20s%-15s%-35s\n", currentPtr-name, currentPtr-teleNo, currentPtr-Email );
currentPtr=currentPtr-nextPtr;
i++;
}
printf( "------------------------------------------------------------\n" );
printf( "总计 %d 个.\n", i );
}
}
/* Save file */
void save( ListNodePtr headPtr )
{
FILE *fp;
ListNodePtr currentPtr=headPtr;
if((fp=fopen("tele.dat","wb"))==NULL) {
printf("无法打开文件.\n");
return;
}
while( currentPtr!=NULL ) {
if( fwrite(currentPtr, ListNodeLen, 1, fp)!=1 ) {
printf( "文件写入出错.\n" );
break;
}
else
currentPtr=currentPtr-nextPtr;
}
fclose( fp );
}
/* Load file */
ListNodePtr load()
{
FILE *fp;
ListNodePtr headPtr, currentPtr;
headPtr=currentPtr=NULL;
if( ( fp=fopen( "tele.dat", "rb" ) )==NULL )
return NULL;
while( !feof( fp ) ) {
currentPtr=(ListNodePtr)malloc( ListNodeLen );
if( fread(currentPtr, ListNodeLen, 1, fp )!=1 ) {
printf( "文件读取失败.\n" );
free( currentPtr );
break;
}
else
insert(&headPtr, currentPtr-name, currentPtr-teleNo, currentPtr-Email );
}
fclose( fp );
return headPtr;
}
/* creat file */
void creatfile() {
FILE *fp;
if( (fp=fopen( "tele.dat", "wb"))==NULL) {
printf( "文件创建失败.\n" );
return;
}
fclose( fp );
}
